利用液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry,LC-MS/MS)的方法,对4种酸乳(优味舒风味发酵乳、风味发酵乳、初乳24+K风味发酵乳和十天风味发酵乳)的肽谱进行分析,分别鉴定到152、125、364条和274条肽段。利...利用液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry,LC-MS/MS)的方法,对4种酸乳(优味舒风味发酵乳、风味发酵乳、初乳24+K风味发酵乳和十天风味发酵乳)的肽谱进行分析,分别鉴定到152、125、364条和274条肽段。利用血管紧张素转换酶(angiotensin converting enzyme,ACE)的抑制活性比较以上4种酸乳的生物活性,在相同质量浓度2.0 mg/L时,4种酸乳ACE抑制率分别为46.84%、42.75%、77.41%和63.84%。初乳24+K风味发酵乳含有肽的数量大、ACE抑制活性高可能与其独特的原料成分相关。对4种酸乳的肽谱及ACE抑制活性的考察,为进一步研究酸乳肽的功能特点和ACE抑制活性提供了理论依据。展开更多
运用反相高效液相色谱(RP-HPLC)对酶解螺蛳腹足肌得到的血管紧张素转换酶(ACE)抑制肽进行两步分离提纯,第一步主要得到8个组分;选取其中活性最高的组分进一步分离,得到2个组分,其中活性较高组分的ACE半抑制浓度为43.5μm o l/L,基本为...运用反相高效液相色谱(RP-HPLC)对酶解螺蛳腹足肌得到的血管紧张素转换酶(ACE)抑制肽进行两步分离提纯,第一步主要得到8个组分;选取其中活性最高的组分进一步分离,得到2个组分,其中活性较高组分的ACE半抑制浓度为43.5μm o l/L,基本为单一肽组分。对提纯的组分分别使用高效液相色谱/电喷雾离子质谱法(HPLC/E S I-M S)和基质辅助激光解吸电离飞行时间质谱法(MALD I-TO F M S)进行分析,同时结合氨基酸组成分析结果,最终得到的肽链一级结构为Lys-G lu-Ile-Trp(KE IW),符合已知的高活性ACE抑制肽的结构规律。经过对两种方法分析过程的比较,认为E S I-M S可以得到多方面的信息,但无法确定肽的序列;MALD I-TO F M S可以得到精确的二级质谱图(m/z精确至0.000 1),从而可以得到确定的肽的序列。展开更多
The complexity and diversity of peptide mixture from protein hydrolysates make their characterization difficult. In this study, a method combining nano LC-MS/MS with molecular docking was applied to identifying and ch...The complexity and diversity of peptide mixture from protein hydrolysates make their characterization difficult. In this study, a method combining nano LC-MS/MS with molecular docking was applied to identifying and characterizing a peptide with angiotensin-? converting enzyme(ACE-I) inhibiting activity from Venerupis philippinarum hydrolysate. Firstly, ethanol supernatant of V. philippinarum hydrolysate was separated into active fractions with chromatographic methods such as ion-exchange chromatography and high performance liquid chromatography in combination. Then seven peptides from active fraction were identified according to the searching result of the MS/MS spectra against protein databases. Peptides were synthesized and subjected to ACE-Iinhibition assay. The peptide NTLTLIDTGIGMTK showed the highest potency with an IC_(50) of 5.75 μmol L^(-1). The molecular docking analysis showed that the ACE-I inhibiting peptide NTLTLIDTGIGMTK bond with residues Glu123, Glu403, Arg522, Glu376, Gln281 and Asn285 of ACE-I. Therefore, active peptides could be identified with the present method rather than the traditional purification and identification strategies. It may also be feasible to identify other food-derived peptides which target other enzymes and receptors with the method developed in this study.展开更多
文摘运用反相高效液相色谱(RP-HPLC)对酶解螺蛳腹足肌得到的血管紧张素转换酶(ACE)抑制肽进行两步分离提纯,第一步主要得到8个组分;选取其中活性最高的组分进一步分离,得到2个组分,其中活性较高组分的ACE半抑制浓度为43.5μm o l/L,基本为单一肽组分。对提纯的组分分别使用高效液相色谱/电喷雾离子质谱法(HPLC/E S I-M S)和基质辅助激光解吸电离飞行时间质谱法(MALD I-TO F M S)进行分析,同时结合氨基酸组成分析结果,最终得到的肽链一级结构为Lys-G lu-Ile-Trp(KE IW),符合已知的高活性ACE抑制肽的结构规律。经过对两种方法分析过程的比较,认为E S I-M S可以得到多方面的信息,但无法确定肽的序列;MALD I-TO F M S可以得到精确的二级质谱图(m/z精确至0.000 1),从而可以得到确定的肽的序列。
基金supported by the Public Science and Technology Research Funds (Projects of Ocean)State Ocean Administration of P. R. China (Nos. 201305007 and 201405017)+3 种基金National High Technology Research and Development Program of China (No. 2013AA093003)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)Jiangsu Qinglan ProjectJiangsu 333 Project
文摘The complexity and diversity of peptide mixture from protein hydrolysates make their characterization difficult. In this study, a method combining nano LC-MS/MS with molecular docking was applied to identifying and characterizing a peptide with angiotensin-? converting enzyme(ACE-I) inhibiting activity from Venerupis philippinarum hydrolysate. Firstly, ethanol supernatant of V. philippinarum hydrolysate was separated into active fractions with chromatographic methods such as ion-exchange chromatography and high performance liquid chromatography in combination. Then seven peptides from active fraction were identified according to the searching result of the MS/MS spectra against protein databases. Peptides were synthesized and subjected to ACE-Iinhibition assay. The peptide NTLTLIDTGIGMTK showed the highest potency with an IC_(50) of 5.75 μmol L^(-1). The molecular docking analysis showed that the ACE-I inhibiting peptide NTLTLIDTGIGMTK bond with residues Glu123, Glu403, Arg522, Glu376, Gln281 and Asn285 of ACE-I. Therefore, active peptides could be identified with the present method rather than the traditional purification and identification strategies. It may also be feasible to identify other food-derived peptides which target other enzymes and receptors with the method developed in this study.
